Film developing and processing tank



29, 56 L. w. GACKI ET AL 2,747,482

FILM DEVELOPING AND PROCESSING TANK Filed Jan. 18, 1954 5 Sheets-Sheet lLEONARD W. GACKI WALTER A. WINFIELD INVENTOR.

BYZWMM ATTORNEY y 1956 L. w. GACKI ET AL FILM DEVELOPING AND PROCESSINGTANK 5 Sheets-Sheet 2 Filed Jan. 18, 1954 FIG. 2

LEONARD W. GAC-KI WALTER A. WINFIELD INVENTOR.

ATTORNEY y 29, 1956 L. w. GACKI ETAL 2,747,482

FILM DEVELOPING AND PROCESSING TANK Filed Jan. 18, 1954 3 Sheets-Sheet 3FIG. 3

LEONARD W. GACKI WALTER A.W|NFIELD INVENTOR.

ATTORNEY FILM DEVELOPING AND PROCESSING TANK Leonard W. Gaclti, Jamaica,and 'Walter A. Winfield,

Bronx, N. Y., assignors to X-ray Instrument Corporation, a corporationof New York Application January 18, 1954, Serial No. 404,739

4 Claims. (Cl. 95%) This invention relates to a film processing anddeveloping tank. Particularly the invention is concerned with a tanksuitable for X-ray film processing wherein a cascade engendering barrierlimits the capacity of one portion of the tank and permits displacementof fluid in excess of the capacity so limited into another portion ofthe tank equipped with separate, accessible drainage facilities.

Film processing and developing tanks of the cascade type have notheretofore been successfully applied to processing X-ray film. Availabletanks of this type have either lacked facilities for preventing orlimiting the corrosive action of residual hypo or other reactants uponthe tank walls or fixtures, or they have not been provided withaccessible facilities for cleaning. conventionally applied tanks of thisdescription are equipped for supporting film hangers and auxiliaryprocessing tanks in the washing fluid suspended from brackets spotWelded or otherwise attached to the tank interior. These and otherprojecting parts obstruct the normal circulation of the washing fluidcausing the formation of pockets of stagnation which render difficultthe maintenance of critically even temperature of the processingsolutions. Sluggishness in the circulatory system further abets theaccumulation of chemically active impurities which may stain, fog orotherwise irretrievably damage valuable negatives in process. A furtherand probably more serious limitation may be attributed to incorrectplacement or extent of the cascade with respect to the circulatory pathof the processing fluid and also with respect to the surface of thefluid within the tank and to the drainage system. irregularities in thedistribution of temperature and in the disposal of waste materials thusare accentuated.

Accordingly, the present invention is directed to the provision of afilm processing and developing tank having an improved, inlet applied,circulatory system.

Another object of the invention is the provision of a cascade type filmdeveloping tank having smoothly contoured, temperature insulated,interior Wall surfaces forming parallel supports for the suspension ofinterchangeable containers for processing solutions and for film rackswithin the liquid in the processing compartment of the tank.

A further object of the invention is the provision in a cascade typefilm processing tank, of improved drainage and cleaning facilities.

A still further object of the invention is an improved cascade formingbarrier within a film processing tank separating the interior of thetank into a processing compartment and a drainage compartment; theprocessing compartment being disposed for the eflicient distributionthroughout the tank interior of controlled temperature by turbulentlycirculated liquid which, subsequently, is cascaded over the barrier intothe drainage compartment.

For a better understanding of the invention together with other andfurther objects thereof, reference is had to the following drawings anddescription in connection with the appended claims defining its scope.

Fig. 1 is an isometric representation of a compartmented, filmprocessing tank with separately contained processing solutions and filmholders suspended in one compartment and with liquid and impurityconcentrating drainage facilities shown in another compartment.

Fig. 2 is a side view of the tank of the invention with a portion of onewall broken away to show the cascade forming barrier, the compartmentedinterior and the associated fluid supply and drainage systems.

Fig. 3 is a rear elevation of the tank of Fig. l, depicting a preferredarrangement of piping and connections appended to a phantom view of thetank.

As shown in Figs. 1 and 2, the film processing and developing tank 1, ofthe invention has walls 2, 8, 9, 1t), and bottom 3, of stainless steelsheeting, temperature insulated by an interior layer 4, of plywood,glass wool or other suitable material. In some instances it may be foundpreferable to provide the interior stainless sheathing with a backing ofwood instead of metal. Tank inlet 5, preferably located in rear wall 8,at a suitable height above the tank bottom, may have threaded extensionsadapted to the application of various types of spraying heads or jetnozzles for altering the direction or characteristic of the circulatorypath of the temperature controlled water delivered to the tank fromconventional tempering valve 21 generally placed within convenient reachof an operator for adjustment of temperature and pressure of the washingfluid in a manner well understood in the art. Drainage outlet 6, throughthe tank bottom, is provided for discharging processing compartment 15,when it is desired to empty the tank. Another outlet 7, the purpose ofwhich is described hereafter, is shown extending vertically through wallsection 8. Longitudinally of opposite walls 2 and 8, and preferablyformed integrally therewith, are parallel projecting supports 11,contoured to present minimum interruption to the path of circulation ofthe water in the processing compartment. These parallel supports extendthe full width of the processing compartment. From them may be suspendedfilm racks l2, and as many auxiliary tanks or containers 13, as may bere quired for the solutions necessary for developing, hardening, fixingand other operations conventionally applied in tanks of thisdescription. To maintain the level of the separate processing solutionsin the auxiliary containers above the normal working level of the liquidin the processing compartment, the auxiliaries have projecting members14, mating with the parallel supports to maintain the open ends of thecontainers above the established liquid level. Similarly equipped forsuspension within the fluid either inthe auxiliaries or in theprocessing compartment, are film racks 12, having protecting members 16,on their upper structures, so arranged that the film 17, within theracks will be suspended completely below the surface of said fluidsduring developing operations.

Auxiliary tanks and film racks are interchangeable so that no delay needbe experienced in their replacement or transfer from one processingoperation to the next.

While the tank of the invention is shown as a coverless structure, itwill be understood that, for reducing oxidation or other purposes, acover could be provided without materially altering the scope of theinvention.

The apparatus so far described is well known in the art and, except asnecessarily included in combination with other elements, forms no partof the invention claimed. As indicated, a developing solution may bemaintained in one auxiliary tank, a hardening and a fixing solution or awetting agent in another. Surrounding the suspended auxiliaryreceptacles and maintained at a level sufliciently below the open endsthereof to prevent seepage thereinto, is Water bath 20, the controlledtemperature of which must be evenly distributed throughout theprocessing compartment.

Processing at excessively high temperature or sudden changes in thetemperature of film processing solutions during development are known tocause reticulation, fog- :ging and other deleterious effects.Retardation of normal chemical reactions may be most advantageouslyovercome in the tank of the invention by maintaining uniform temperatureof all solutions at a predetermined level established for the work inprocess. To this end, the temperature of the water bath in theprocessing compartment is carefully adjusted and controlled at thetempering valve or other suitable control means and is transmitted bycontinuous circulation of the water in contact with the auxiliary tanks,thence to the solutions within them. Turbulence is continuously appliedto the water in the processing compartment by the forceful injection ofa continuous stream through inlet 5, at a predetermined rate of flowusually not in excess of nine gallons per minute. Regardless of the rateof flow or the characteristic path imparted to the circulation of thewater by the nozzle applied at the inlet, the level of the Water in theprocessing compartment can never rise above the height established bythe top of barrier 30, which is shown extending longitudinally of thecomplete interior width dimension of the tank between oppositely spacedwalls 9 and ill. Water in excess of the capacity established by thebarrier is cascaded over the barrier into drainage compartment 31. Therate of drainage of this compartment, as established by as many screenedoutlets 7, as may be required, is considerably in excess of the tankinlet capacity, thus assuring that the level of the water in theprocessing compartment cannot rise to a height endangering seepage intothe auxiliary tanks. It is important to note that the cascade formingbarrier 30, extends the full interior width dimension between walls 9and 14). This is also the full width extension of processing compartment15, and drainage compartment 31. The cascade over the barrier thuseffectively drains off along the entire surface of the turbulentlycirculated fluid in the processing compartment, the comprehensive extentof the spillway thus becomes a factor in the prevention of stagnationand in the eflicient disposal of waste and impurities carried by thecascaded fluid.

Heavier waste materials such as silver particles washed from thenegatives in process will sink to the bottom of the processingcompartment whence eventually they may be drained off through bottomoutlet 6. Lighter waste materials, including scum forming drip, carriedby the turbulent washing stream, will swirl to the surface of the liquidin the processing compartment to be cascaded into the drainage system.As is best shown in Fig. 2, the smooth contour of the barrier andchannelled receptacle 31 with the extended, outer rear wall of the tank,are efiective as a splash reducer, the wall serving to confine thecascaded liquid within the drainage compartment without spillage. Thespecific location of the gutter with respect to the barrier and itsadjacency to the top of tank ll, provide easy access from outside thetank during processing operations for clearing drains and wiping awaythe residual accumulation of scum and solid impurities which mightotherwise clog or impair the functioning of the drainage system.

The shelf like protrusion of barrier and gutter forming wall 8, boundedon each side by the side walls of the tank provides a recessed areawithin which piping, valves and accessories may be protectively housed.The preferred arrangement of fluid supply and drainage system is shownin Fig. 3. The recessed enclosure of plumbing connections thereindisplayed, permits installation of the tank flush with the wall of alaboratory or other interior with no projecting parts exposed to damagefrom outside the tank and with ample protection against drip or overflowof water or corrosive'solutions from within.

Drainage compartment or receptacle 31, is directly above inlet 5. It isthus located in its most effective position with respect to thecirculatory path of the processing liquid and also with respect to thedrains 7, in which the cascaded overflow is concentrated andgravitationally delivered through suitable piping shown in communicationalso with main tank drain 6. Thus, completely within the identifiedstructure comprising the tank of the invention, from inlet to finaldisposal, is maintained an uninterrupted flow of temperature controlledliquid, evenly distributed to all critical processing areas. To insureuniformity of drainage of waste water and impurities over the barrier,levelling feet 40, may be suitably adjusted at each corner of the maintank.

Illuminated viewing boxes 50, for observing the progress of filmdevelopment in the darkroom, may be installed adjacent to the tank as inFig. 1. One view box may house a white light of suitable intensity, theother may contain a safelight having a protecting filter or screen fortransmitting only light of a wavelength incapable of damaging partiallydeveloped negatives. if the view boxes are located directly above thedrainage compartment, the drip from the film may be prevented fromcontaminating the solutions within the separate auxiliary containers.

While the material of the tank has been specified as stainless steel,hard rubber, synthetic resin, or other corrosion resisting materialwould equally serve the purposes of the invention. Where desired, thetank wall structure, including the overhanging drainage receptacle, maybe unitarily molded of suitable material such as a ceramic.

Having described the apparatus, what is believed to constitute the novelimprovement inhering therein is specified in the following claims:

1. In a film developing and processing tank comprising a processingcompartment; a drainage compartment extending outwardly of a wall ofsaid processing compartment; a barrier extending between opposite wallsof said tank and common to said compartments; means for circulatingfluid in said processing compartment lengthwise between processing unitsinterchangeably suspended therein and in a direction normal to saidbarrier causing portions of said fluid to cascade thereover; a drainextending vertically through the bottom of said drainage compartment fordisposal of said cascaded fluid outside said tank.

2. In an X-ray film processing tank equipped for con trol by fluidcontact of the temperature of solutions in separately suspendedauxiliary containers within a processing compartment, the improvementcomprising a barrier extending the full width of said processingcompartment at a height substantially below the tops of said containersin suspension; a relatively shallow bottomed compartment bounded by saidbarrier and extensions of the walls of said processing compartment;means circulating temperature controlled fluid in a direction normal ofsaid barrier and means for vertically disposing of fluid cascaded oversaid barrier exteriorly of the walls of said tank.

3. A film processing and developing tank of the cascade type comprisinga film processing compartment; inlet means in said compartment forcirculating liquid at a controlled temperature; means extending alongthe entire surface of said circulated liquid for cascading excessthereof into a receptacle having an outlet therein, said receptacle andsaid outlet being located within the casing of said tank at a heightsubstantially above said inlet.

4. A processing and developing tank for X-ray fihn comprisingtemperature insulated walls and a bottom surrounding a processingcompartment; an extension of one of said walls forming a barrier and ashallow drainage receptacle having at least one outlet; the height ofsaid barrier and the discharging capacity of said outlet establishingthe level of the liquid in said compartment; and a normally closed,second ouilct adaptable to drainage of the liquid remaining in saidprocessing compartment below the liquid level established by saidbarrier.

References Cited in the file of this patent UNITED STATES PATENTSHopkins Aug. 12, 1930 Murk June 7, 1932 Moore Aug. 24, 1943 Powers et alOct. 11, 1949 Traiber July 31, 1951 Sardeson et al Sept. 22, 1953

